910 resultados para Myocardial revascularization


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Two young women with angiographically normal coronary arteries suffered an acute myocardial infarction. Both were found to have a patent foramen ovale (PFO), the likely pathway of a paradoxical embolus causing the infarction. The PFOs were diagnosed and closed percutaneously with an Amplatzer PFO Occluder during the emergency coronary angiography.

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AIMS: Myocardial blood flow (MBF) is the gold standard to assess myocardial blood supply and, as recently shown, can be obtained by myocardial contrast echocardiography (MCE). The aims of this human study are (i) to test whether measurements of collateral-derived MBF by MCE are feasible during elective angioplasty and (ii) to validate the concept of pressure-derived collateral-flow assessment. METHODS AND RESULTS: Thirty patients with stable coronary artery disease underwent MCE of the collateral-receiving territory during and after angioplasty of 37 stenoses. MCE perfusion analysis was successful in 32 cases. MBF during and after angioplasty varied between 0.060-0.876 mL min(-1) g(-1) (0.304+/-0.196 mL min(-1) g(-1)) and 0.676-1.773 mL min(-1) g(-1) (1.207+/-0.327 mL min(-1) g(-1)), respectively. Collateral-perfusion index (CPI) is defined as the rate of MBF during and after angioplasty varied between 0.05 and 0.67 (0.26+/-0.15). During angioplasty, simultaneous measurements of mean aortic pressure, coronary wedge pressure, and central venous pressure determined the pressure-derived collateral-flow index (CFI(p)), which varied between 0.04 and 0.61 (0.23+/-0.14). Linear-regression analysis demonstrated an excellent agreement between CFI(p) and CPI (y=0.88 x +0.01; r(2)=0.92; P<0.0001). CONCLUSION: Collateral-derived MBF measurements by MCE during angioplasty are feasible and proved that the pressure-derived CFI exactly reflects collateral relative to normal myocardial perfusion in humans.

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AIMS: The adaptation of the myocardial microcirculation in humans to pathologic and physiologic stress has not been examined in vivo so far. We sought to test whether the relative blood volume (rBV) measured by myocardial contrast echocardiography (MCE) can differentiate between left ventricular (LV) hypertrophy (LVH) in hypertensive heart disease and athlete's heart. METHODS AND RESULTS: Four groups were investigated: hypertensive patients with LVH (n = 15), semi-professional triathletes with LVH (n = 15), professional football players (n = 15), and sedentary control individuals without cardiovascular disease (n = 15). MCE was performed at rest and during adenosine-induced hyperaemia. The rBV (mL mL(-1)), its exchange frequency (beta, min(-1)), and myocardial blood flow (mL min(-1) g(-1)) were derived from steady state and refill sequences of ultrasound contrast agent. Hypertensive patients had lower rBV (0.093 +/- 0.013 mL mL(-1)) than triathletes (0.141 +/- 0.012 mL mL(-1), P < 0.001), football players (0.129 +/- 0.014 mL mL(-1), P < 0.001), and sedentary individuals (0.126 +/- 0.018 mL mL(-1), P < 0.001). Conversely, the exchange frequency (beta) was significantly higher in hypertensive patients (11.3 +/- 3.8 min(-1)) than in triathletes (7.4 +/- 1.8 min(-1)), football players (7.7 +/- 2.3 min(-1)), and sedentary individuals (9.0+/-2.5 min(-1)). An rBV below 0.114 mL mL(-1) distinguished hypertensive patients and triathletes with a sensitivity of 93% and a specificity of 100%. CONCLUSION: Pathologic and physiologic LVH were differentiated non-invasively and accurately by rBV, a measure of vascularisation assessed by MCE.

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BACKGROUND: Transferring patients with ST-elevation myocardial infarction (STEMI) for primary percutaneous coronary intervention (PCI) from a community hospital to a PCI centre has been evaluated in randomised trials and shown to be safe and effective. A prolonged transfer time may restrict the benefit of this strategy. AIM: We sought to assess 1) safety of transfer from Neuchâtel to Berne, 2) time intervals of patients transferred either directly from on-site or after evaluation in the local emergency room, and 3) clinical long-term outcome. METHODS AND RESULTS: 42 patients with STEMI eligible for reperfusion therapy were prospectively included between January 2003 and June 2004. Twenty patients (48%, group 1) were directly transferred to the PCI centre from on-site. Twenty-two were transferred after initial treatment in the local emergency room: 11 patients (26%, group 2) presented spontaneously at the hospital and 11 patients (26%, group 3) were admitted by the rescue team. No major complication occurred during transport. Median transport time was 33 minutes. Median time from first healthcare contact to balloon consisted of 131 minutes in group 1, 158 minutes in group 2 and 174 minutes in group 3. The overall rate of Major Adverse Cardiac Events (MACE) at 6 months amounted to 9.5%. CONCLUSIONS: Transfer for primary PCI of our patients with acute STEMI was safe. Direct transfer from on-site to the PCI centre reduced the time of ischaemia. The overall MACE rate was low.

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AIMS: Postmortem magnetic resonance (MRI) imaging is currently evaluated as alternative to traditional autopsy and myocardial infarction plays a key role therein. The aim of this study is to determine the suitability of postmortem MRI in infarction age staging. METHODS AND RESULTS: In eight human forensic corpses presenting with a total of 11 myocardial infarcted areas, short-axis, transversal, and longitudinal long-axis images (T1, T2, stir, flair) were acquired in situ on a 1.5 T system. During subsequent autopsy, the section technique was adapted to short-axis images. Histological investigations were performed along the entire circumference of the left ventricle to correlate the signal alteration in MR to the histological appearance. Two peracute infarctions were not detected in MRI and autopsy. Four acute infarcted areas presented with decreased signal in necrotic centres and increased signal in marginal myocardial regions (T2-weighted). T1-weighted images showed local hyperintensities when intramyocardial haemorrhage occurred. Four cases showed subacute infarctions with hyperintense regions in T2-weighted images and no signal alteration in T1-weighted images. Four chronic myocardial infarctions showed distinctively decreased signals in all applied sequences. CONCLUSION: Postmortem MRI demonstrates myocardial infarction in situ and allows for an infarction age estimation based on the signal behaviour.

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BACKGROUND: Post-traumatic stress disorder (PTSD) may develop in the aftermath of an acute myocardial infarction (MI). Whether PTSD is a risk factor for cardiovascular disease (CVD) is elusive. The biological mechanisms linking PTSD with atherosclerosis are unclear. DESIGN: A critical review of 31 studies in the English language pursuing three aims: (i) to estimate the prevalence of PTSD in post-MI patients; (ii) to investigate the association of PTSD with cardiovascular endpoints; and (iii) to search for low-grade systemic inflammatory changes in PTSD pertinent to atherosclerosis. METHODS: We located studies by PubMed electronic library search and through checking the bibliographies of these sources. RESULTS: The weighted prevalence of PTSD after MI was 14.7% (range 0-25%; a total of 13 studies and 827 post-MI patients). Two studies reported a prospective association between PTSD and an increased risk of cardiovascular readmission in post-MI patients and of cardiovascular mortality in combat veterans, respectively. In a total of 11 studies, patients with PTSD had increased rates of physician-rated and self-reported cardiovascular diseases. Various cytokines and C-reactive protein were investigated in a total of seven studies suggesting that PTSD confers a pro-inflammatory state. CONCLUSIONS: Increasing evidence suggests that PTSD specifically related to MI develops considerably frequently in post-MI patients. More research is needed in larger cohorts applying a population design to substantiate findings suggesting PTSD is an atherogenic risk factor and to understand better the suspected behavioural and biological mechanisms involved.

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Cell-based therapies and tissue engineering initiatives are gathering clinical momentum for next-generation treatment of tissue deficiencies. By using gravity-enforced self-assembly of monodispersed primary cells, we have produced adult and neonatal rat cardiomyocyte-based myocardial microtissues that could optionally be vascularized following coating with human umbilical vein endothelial cells (HUVECs). Within myocardial microtissues, individual cardiomyocytes showed native-like cell shape and structure, and established electrochemical coupling via intercalated disks. This resulted in the coordinated beating of microtissues, which was recorded by means of a multi-electrode complementary metal-oxide-semiconductor microchip. Myocardial microtissues (microm3 scale), coated with HUVECs and cast in a custom-shaped agarose mold, assembled to coherent macrotissues (mm3 scale), characterized by an extensive capillary network with typical vessel ultrastructures. Following implantation into chicken embryos, myocardial microtissues recruited the embryo's capillaries to functionally vascularize the rat-derived tissue implant. Similarly, transplantation of rat myocardial microtissues into the pericardium of adult rats resulted in time-dependent integration of myocardial microtissues and co-alignment of implanted and host cardiomyocytes within 7 days. Myocardial microtissues and custom-shaped macrotissues produced by cellular self-assembly exemplify the potential of artificial tissue implants for regenerative medicine.

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OBJECTIVE(S): Even though the mechanism is not clearly understood, direct intramyocardial cell transplantation has demonstrated potential to treat patients with severe heart failure. We previously reported on the bioengineering of myoblast-based constructs. We investigate here the functional outcome of infarcted hearts treated by implantation of myoblast-seeded scaffolds. METHODS: Adult Lewis rats with echocardiography-confirmed postinfarction reduced ejection fraction (48.3% +/- 1.1%) were randomized to (1) implantation of myoblast-seeded polyurethane patches at the site of infarction (PU-MyoB, n = 11), (2) implantation of nonseeded polyurethane patches (PU, n = 11), (3) sham operation (Sham, n = 12), and (4) direct intramyocardial myoblast injection (MyoB, n = 11). Four weeks later, the functional assessment by echocardiography was repeated, and we additionally performed left ventricular catheterization plus histologic studies. RESULTS: The ejection fraction significantly decreased in the PU (39.1% +/- 2.3%; P = .02) and Sham (39.9% +/- 3.5%; P = .04) groups, whereas it remained stable in the PU-MyoB (48.4% +/- 3.1%) and MyoB (47.9% +/- 3.0%) groups during the observation time. Similarly, left ventricular contractility was significantly higher in groups PU-MyoB (4960 +/- 266 mm Hg/s) and MyoB (4748 +/- 304 mm Hg/s) than in groups PU (3909 +/- 248 mm Hg/s, P = .01) and Sham (4028 +/- 199 mm Hg/s, P = .01). Immunohistology identified a high density of myoblasts within the seeded scaffolds without any migration toward the host cardiac tissue and no evidence of cardiac cell differentiation. CONCLUSIONS: Myoblast-seeded polyurethane scaffolds prevent post-myocardial infarction progression toward heart failure as efficiently as direct intramyocardial injection. The immunohistologic analysis suggests that an indirect mechanism, potentially a paracrine effect, may be assumed.

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The rodent model of myocardial infarction (MI) is extensively used in heart failure studies. However, long-term follow-up of echocardiographic left ventricular (LV) function parameters such as the myocardial performance index (MPI) and its ratio with the fractional shortening (LVFS/MPI) has not been validated in conjunction with invasive indexes, such as those derived from the conductance catheter (CC). Sprague-Dawley rats with left anterior descending coronary artery ligation (MI group, n = 9) were compared with a sham-operated control group (n = 10) without MI. Transthoracic echocardiography (TTE) was performed every 2 wk over an 8-wk period, after which classic TTE parameters, especially MPI and LVFS/MPI, were compared with invasive indexes obtained by using a CC. Serial TTE data showed significant alterations in the majority of the noninvasive functional and structural parameters (classic and novel) studied in the presence of MI. Both MPI and LVFS/MPI significantly (P < 0.05 for all reported values) correlated with body weight (r = -0.58 and 0.76 for MPI and LVFS/MPI, respectively), preload recruitable stroke work (r = -0.61 and 0.63), LV end-diastolic pressure (LVEDP) (r = 0.82 and -0.80), end-diastolic volume (r = 0.61 and -0.58), and end-systolic volume (r = 0.46 and -0.48). Forward stepwise linear regression analysis revealed that, of all variables tested, LVEDP was the only independent determinant of MPI (r = 0.84) and LVFS/MPI (r = 0.83). We conclude that MPI and LVFS/MPI correlate strongly and better than the classic noninvasive TTE parameters with established, invasively assessed indexes of contractility, preload, and volumetry. These findings support the use of these two new noninvasive indexes for long-term analysis of the post-MI LV remodeling.

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AIMS: A registry mandated by the European Society of Cardiology collects data on trends in interventional cardiology within Europe. Special interest focuses on relative increases and ratios in new techniques and their distributions across Europe. We report the data through 2004 and give an overview of the development of coronary interventions since the first data collection in 1992. METHODS AND RESULTS: Questionnaires were distributed yearly to delegates of all national societies of cardiology represented in the European Society of Cardiology. The goal was to collect the case numbers of all local institutions and operators. The overall numbers of coronary angiographies increased from 1992 to 2004 from 684 000 to 2 238 000 (from 1250 to 3930 per million inhabitants). The respective numbers for percutaneous coronary interventions (PCIs) and coronary stenting procedures increased from 184 000 to 885 000 (from 335 to 1550) and from 3000 to 770 000 (from 5 to 1350), respectively. Germany was the most active country with 712 000 angiographies (8600), 249 000 angioplasties (3000), and 200 000 stenting procedures (2400) in 2004. The indication has shifted towards acute coronary syndromes, as demonstrated by rising rates of interventions for acute myocardial infarction over the last decade. The procedures are more readily performed and perceived safer, as shown by increasing rate of "ad hoc" PCIs and decreasing need for emergency coronary artery bypass grafting (CABG). In 2004, the use of drug-eluting stents continued to rise. However, an enormous variability is reported with the highest rate in Switzerland (70%). If the rate of progression remains constant until 2010 the projected number of coronary angiographies will be over three million, and the number of PCIs about 1.5 million with a stenting rate of almost 100%. CONCLUSION: Interventional cardiology in Europe is ever expanding. New coronary revascularization procedures, alternative or complementary to balloon angioplasty, have come and gone. Only stenting has stood the test of time and matured to the default technique. Facilitated access to PCI, more complete and earlier detection of coronary artery disease promise continued growth of the procedure despite the uncontested success of prevention.

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CONTEXT: Compared with bare metal stents, sirolimus-eluting and paclitaxel-eluting stents have been shown to markedly improve angiographic and clinical outcomes after percutaneous coronary revascularization, but their performance in the treatment of de novo coronary lesions has not been compared in a prospective multicenter study. OBJECTIVE: To compare the safety and efficacy of sirolimus-eluting vs paclitaxel-eluting coronary stents. DESIGN: Prospective, randomized comparative trial (the REALITY trial) conducted between August 2003 and February 2004, with angiographic follow-up at 8 months and clinical follow-up at 12 months. SETTING: Ninety hospitals in Europe, Latin America, and Asia. PATIENTS: A total of 1386 patients (mean age, 62.6 years; 73.1% men; 28.0% with diabetes) with angina pectoris and 1 or 2 de novo lesions (2.25-3.00 mm in diameter) in native coronary arteries. INTERVENTION: Patients were randomly assigned in a 1:1 ratio to receive a sirolimus-eluting stent (n = 701) or a paclitaxel-eluting stent (n = 685). MAIN OUTCOME MEASURES: The primary end point was in-lesion binary restenosis (presence of a more than 50% luminal-diameter stenosis) at 8 months. Secondary end points included 1-year rates of target lesion and vessel revascularization and a composite end point of cardiac death, Q-wave or non-Q-wave myocardial infarction, coronary artery bypass graft surgery, or repeat target lesion revascularization. RESULTS: In-lesion binary restenosis at 8 months occurred in 86 patients (9.6%) with a sirolimus-eluting stent vs 95 (11.1%) with a paclitaxel-eluting stent (relative risk [RR], 0.84; 95% confidence interval [CI], 0.61-1.17; P = .31). For sirolimus- vs paclitaxel-eluting stents, respectively, the mean (SD) in-stent late loss was 0.09 (0.43) mm vs 0.31 (0.44) mm (difference, -0.22 mm; 95% CI, -0.26 to -0.18 mm; P<.001), mean (SD) in-stent diameter stenosis was 23.1% (16.6%) vs 26.7% (15.8%) (difference, -3.60%; 95% CI, -5.12% to -2.08%; P<.001), and the number of major adverse cardiac events at 1 year was 73 (10.7%) vs 76 (11.4%) (RR, 0.94; 95% CI, 0.69-1.27; P = .73). CONCLUSION: In this trial comparing sirolimus- and paclitaxel-eluting coronary stents, there were no differences in the rates of binary restenosis or major adverse cardiac events. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00235092.

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BACKGROUND: Mortality and morbidity from acute myocardial infarction (AMI) remain high. Intravenous magnesium started early after the onset of AMI is thought to be a promising adjuvant treatment. Conflicting results from earlier trials and meta-analyses warrant a systematic review of available evidence. OBJECTIVES: To examine the effect of intravenous magnesium versus placebo on early mortality and morbidity. SEARCH STRATEGY: We searched CENTRAL (The Cochrane Library Issue 3, 2006), MEDLINE (January 1966 to June 2006) and EMBASE (January 1980 to June 2006), and the Chinese Biomedical Disk (CBM disk) (January 1978 to June 2006). Some core Chinese medical journals relevant to the cardiovascular field were hand searched from their starting date to the first-half year of 2006. SELECTION CRITERIA: All randomized controlled trials that compared intravenous magnesium with placebo in the presence or absence of fibrinolytic therapy in addition to routine treatment were eligible if they reported mortality and morbidity within 35 days of AMI onset. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the trial quality and extracted data using a standard form. Odds ratio (OR) were used to pool the effect if appropriate. Where heterogeneity of effects was found, clinical and methodological sources of this were explored. MAIN RESULTS: For early mortality where there was evidence of heterogeneity, a fixed-effect meta-analysis showed no difference between magnesium and placebo groups (OR 0.99, 95%CI 0.94 to 1.04), while a random-effects meta-analysis showed a significant reduction comparing magnesium with placebo (OR 0.66, 95% CI 0.53 to 0.82). Stratification by timing of treatment (< 6 hrs, 6+ hrs) reduced heterogeneity, and in both fixed-effect and random-effects models no significant effect of magnesium was found. In stratified analyses, early mortality was reduced for patients not treated with thrombolysis (OR=0.73, 95% CI 0.56 to 0.94 by random-effects model) and for those treated with less than 75 mmol of magnesium (OR=0.59, 95% CI 0.49 to 0.70) in the magnesium compared with placebo groups.Meta-analysis for the secondary outcomes where there was no evidence of heterogeneity showed reductions in the odds of ventricular fibrillation (OR=0.88, 95% CI 0.81 to 0.96), but increases in the odds of profound hypotension (OR=1.13, 95% CI 1.09 to 1.19) and bradycardia (OR=1.49, 95% CI 1.26 to 1.77) comparing magnesium with placebo. No difference was observed for heart block (OR=1.05, 95% CI 0.97-1.14). For those outcomes where there was evidence of heterogeneity, meta-analysis with both fixed-effect and random-effects models showed that magnesium could decrease ventricular tachycardia (OR=0.45, 95% CI 0.31 to 0.66 by fixed-effect model; OR=0.40, 95% CI 0.19 to 0.84 by random-effects model) and severe arrhythmia needing treatment or Lown 2-5 (OR=0.72, 95% CI 0.60 to 0.85 by fixed-effect model; OR=0.51, 95% CI 0.33 to 0.79 by random-effects model) compared with placebo. There was no difference on the effect of cardiogenic shock between the two groups. AUTHORS' CONCLUSIONS: Owing to the likelihood of publication bias and marked heterogeneity of treatment effects, it is essential that the findings are interpreted cautiously. From the evidence reviewed here, we consider that: (1) it is unlikely that magnesium is beneficial in reducing mortality both in patients treated early and in patients treated late, and in patients already receiving thrombolytic therapy; (2) it is unlikely that magnesium will reduce mortality when used at high dose (>=75 mmol); (3) magnesium treatment may reduce the incidence of ventricular fibrillation, ventricular tachycardia, severe arrhythmia needing treatment or Lown 2-5, but it may increase the incidence of profound hypotension, bradycardia and flushing; and (4) the areas of uncertainty regarding the effect of magnesium on mortality remain the effect of low dose treatment (< 75 mmol) and in patients not treate...